Sign up for idoneit.com's free email service, and every evening they'll drop a quick note in your inbox asking you what you did that day. The data from your reply is automatically added to their running calendar, so you can track your productivity progress, and the potential embarrassment of having to type out, "did nothing", is sure to keep you on your toes... Sort of like a nagging parent checking up on you to make sure you've done your homework.